Flavonoids are an important type of bioactive substance contained in jujubes. Flavonol synthase (FLS) is a key enzyme for the synthesis of flavonoids such as flavonols and anthocyanins. To study the biological functions of
FLS in jujubes, we cloned the
ZjFLS gene; analyzed
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Flavonoids are an important type of bioactive substance contained in jujubes. Flavonol synthase (FLS) is a key enzyme for the synthesis of flavonoids such as flavonols and anthocyanins. To study the biological functions of
FLS in jujubes, we cloned the
ZjFLS gene; analyzed its physicochemical properties and evolutionary relationships; and then conducted an expression characteristic analysis, subcellular localization, prokaryotic expression and heterologous overexpression in
Arabidopsis thaliana. The results showed that the length of
ZjFLS is 951 bp, and it encodes 316 amino acids. A sequence analysis revealed that
ZjFLS exhibited a high degree of conservation in evolution. The results of a qRT-PCR analysis indicated that the
ZjFLS gene could be expressed in different tissues of jujube: the expression level was the highest in the leaves, followed by the flowers, and the lowest was in the fruits. Within these expression levels, it was higher in young leaves than in mature leaves and higher in the white-ripe-stage fruits than in the semi-red-stage fruits. Subcellular localization indicated that the
ZjFLS gene was located in the nucleus, cytoplasmic matrix, and cytoplasmic membrane. Our research findings show that the ZjFLS protein can be induced and obtained in the prokaryotic expression system and successfully purified. It mainly exists in the form of inclusion bodies and has a relatively low content in the soluble supernatant. The total flavonoid content of
Arabidopsis thaliana strains with a heterologous overexpression of the
ZjFLS gene was significantly higher than that of the wild type, confirming that the
ZjFLS gene can promote the biosynthesis of flavonoid substances.
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